Docker is a popular tool that allows users to easily package, deploy, and run applications in a containerized environment.

In this blog post, we will provide a beginner’s guide to using Docker with a FastAPI application.
Before we get started, it’s important to understand what Docker is and why it’s useful.

Docker is a containerization platform that allows developers to package their applications and dependencies into a single, isolated container. This makes it easy to deploy and run applications in a consistent environment, regardless of the underlying infrastructure.

Also it reduces the issues such as it works on my computer 😛

To use Docker with a FastAPI application, you will need to have Docker installed on your system. You can download Docker from the official website and follow the instructions for your operating system to set it up.

Once you have Docker installed, you can create a Dockerfile for your FastAPI application. We have already created a CRUD based FastAPI application and we are going to dockerize the same.

A Dockerfile is a text file that contains instructions for building a Docker image. To create a Dockerfile for a FastAPI application, you can use the following template:

# Start from the official Python image 
FROM python:3.8 

# Set the working directory 
WORKDIR /app 

# Copy the requirements file 
COPY requirements.txt . 

# Install the requirements 
RUN pip install -r requirements.txt 

# Copy the application code 
COPY . . 

# Expose the application's port 
EXPOSE 8000 

# Run the application 
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]
Code language: Python (python)

Save this file as Dockerfile and most of the code editors available detect it as docker file in your root directory. If your code editor is not able to detect, try updating or installing extention related to docker.  After adding the dockerfile the code structure should look something like this

main.py
requirements.txt
database.py
models.py
schemes.py
README.md
Dockerfile
Code language: Python (python)

This Dockerfile specifies that we are starting from the official Python image, setting the working directory to /app, copying the requirements file, installing the requirements, copying the application code, exposing the application’s port, and running the application using uvicorn.

Once you have created the Dockerfile, you can build a Docker image for your FastAPI application using the docker build command. For example, if you want to build an image named my-fastapi-app, you can use the following command:

docker build -t my-fastapi-app .
Code language: Python (python)

This will build the Docker image using the instructions in the Dockerfile. Once the image is built, you can run it using the docker run command.

For example, if you want to run the my-fastapi-app image, you can use the following command:

docker run -p 8000:8000 my-fastapi-app
Code language: Python (python)

This will run the Docker image, exposing the application’s port on port 8000. You can then access the FastAPI application at http://localhost:8000.

In this blog post, we provided a beginner’s guide to using Docker with a FastAPI application. We showed how to create a Dockerfile, build a Docker image, and run the image to deploy the FastAPI application. Using Docker can make it easy to deploy and run your FastAPI application in a consistent environment.

You can get the full code from github by clicking here FastAPI Todo Application